There are few things cooler than a fish that can walk on land, or a rodent that can fly, but despite all the amazing adaptations evolution has seen fit to create upon this Earth, I cannot think of an animal that is equally skilled in two transportation media, let alone all three.

So my question is this: can you envision a creature that can move equally well through water and air, as well as on land? Specifically, I'd want it to be able to hunt in all three areas, as probably the main reason for evolving this way would be to find more food sources. So, what would it look like, how would it move, where would it sleep, et cetera.

The best thing I can think of currently is a duck. I'm hoping someone can come up with something more fearsome (corkscrew genitalia aside).

  • 6
    $\begingroup$ After reading your second paragraph, I starting thinking about it and was going to post "A duck." Then I saw your third paragraph... Even then it's not equally well; it's very well, but not equally. When you say "equally well," what's your metric? Same velocity in each environment? Or just that it considers them all native environments, even though it may be slower in the water than in the air? $\endgroup$
    – iAdjunct
    Mar 10, 2015 at 14:38
  • $\begingroup$ @iAdjunct Like I said, it should be able to hunt things that live there. For instance, it should be able to attack birds in the air, fish in the sea, and mammals/reptiles on land. $\endgroup$ Mar 10, 2015 at 14:44
  • 2
    $\begingroup$ It's not a duck, but loons are similar and much 'cooler' than ducks, scale them up a bit, give them razer sharp bills etc. the en.wikipedia.org/wiki/Phorusrhacidae was pretty scary (though flightless and land bound) $\endgroup$
    – bowlturner
    Mar 10, 2015 at 15:14
  • 1
    $\begingroup$ What would cause a species to evolve to specialize into the three environments. From a evolutionary biology point of view, this is an unstable situation, similar to the Galapagos Islands. There a few species diverged to fill each niche in the eco system well. Consider if one member of your animal mutates and finds itself much more capable of surviving at sea than others. Its offspring would then spend an inordinate amount of time in the sea compared to others of the species, and they would out compete the others, who would leave the sea. $\endgroup$
    – Aron
    Mar 11, 2015 at 3:16
  • $\begingroup$ "Like I said, it should be able to hunt things that live there. For instance, it should be able to attack birds in the air, fish in the sea, and mammals/reptiles on land." --> Seagulls? $\endgroup$ Mar 11, 2015 at 12:49

11 Answers 11


Dolphin Bats

Dolphin Bats are a family in the mammal-analogs of Persius 8. They vaguely resemble Terran bats with some adaptions for water (hence the name), and range from 10 cm to 2 meters in length depending on species. They are omnivorous, preferring small animals and insects but also occasionally eating berries and fruits when hunting is scarce.

Dolphin Bats live in coastal areas. Depending on the time of year, they either hunt in the water, in the air, or on the land. Due to its unique orbit and inclination, Persius 8 has dramatic storms for half the year, during which it is impossible to fly. The other half of the year has a more standard climate structure.

During half of this storm period, Dolphin Bats hunt underwater, feeding on the fertile ocean life. However, halfway through the storm season the Dolphin Bat's natural predator - the Carnival Shark - starts to reach adolescence (see Bryer's Appendix B for details). At this point they are forced out of the water, and hunt on land for the remainder of the storm season. At that point they return to the air, feasting on the large amount of insects that appear during this time period.

Dolphin Bats have several unique adaptations to each environment. They put on significant weight during the storm season to allow for better water adaptability, building significant additional muscle mass on their legs (which they use alternatively for swimming, and then later for running). The Dolphin Bat's primary weapon is a sharp beak, which works equally well in each environment. At the end of the storm season the Dolphin Bats lose muscle mass in their legs and bulk up their wing muscles to start the cycle anew. Dolphin Bat "fur" also seems to change, becoming more oily during the storm season for water slicking.

Due to this cyclic nature, which is driven by climate and predators, Dolphin Bats are never fully adapted to all three environments at one time - at each point in the year they will be optimized to only one, although they are still somewhat capable in the others.

  • 3
    $\begingroup$ +1 for cyclical adaptations. It both explains why it'd happen, and how it could without as much hindrance as being equally good at all three things at once. Though I'd like an example of an animal that builds/loses muscle mass cyclically, that seems like the least plausible part. $\endgroup$ Mar 10, 2015 at 19:04
  • $\begingroup$ Humans? :) I know I do it depending on how much hockey I'm playing... but really no, I don't have any amazing examples of earth animals. It just seemed like something that could be plausible, although they likely have to gorge themselves each time to cover the energy requirements. $\endgroup$ Mar 10, 2015 at 19:14
  • $\begingroup$ Yeah, I guess the muscles could build up pretty fast as long as something was telling them it was necessary and supplying enough nutrients. The animal would probably have to stockpile food somewhere and eat it during their transition phases. $\endgroup$ Mar 10, 2015 at 19:17
  • 3
    $\begingroup$ Also, based on your air-phase and @Neil's answer, I got to thinking, what if the prey was cyclical as well? Perhaps a bug that lays its eggs in water, then hatches into the air, then returns to the ground to gather nutrients before the floods come and the cycle repeats. Or whatever cycle would match up with the Dolphin Bat. $\endgroup$ Mar 10, 2015 at 19:23

Creatures that move hunt equally well throughout air, land or sea. All your terrains are belong to us.

http://shadered.weebly.com/uploads/2/6/3/0/26303314/4367529.jpg?486 http://media.treehugger.com/assets/images/2011/10/kingfisher-lizard.jpg.644x0_q100_crop-smart.jpg


Wiki excerpt:

Kingfishers feed on a wide variety of items. They are most famous for hunting and eating fish, and some species do specialize in catching fish, but other species take crustaceans, frogs and other amphibians, annelid worms, molluscs, insects, spiders, centipedes, reptiles (including snakes) and even birds and mammals. Individual species may specialize in a few items or take a wide variety of prey, and for species with large global distributions different populations may have different diets.

Woodland and forest kingfishers take mainly insects, particularly grasshoppers, whereas the water kingfishers are more specialized in taking fish. The red-backed kingfisher has been observed hammering into the mud nests of fairy martins to feed on their nestlings.

Kingfishers usually hunt from an exposed perch, when a prey item is observed the kingfisher swoops down to snatch it, then returns to the perch. Kingfishers of all three families beat larger prey on a perch in order to kill the prey and to dislodge or break protective spines and bones. Having beaten the prey it is manipulated and then swallowed. The shovel-billed kookaburra uses its massive wide bill as a shovel in order to dig for worms in soft mud.


Just to totally change angle of thought, I'm trying to go small scale. Everyone's going "big" thinking "bigger is better", however, some of the most aggressive and versatile creatures out there are smaller insects.

Especially the flyers .. they don't fly like birds .. they almost defy physics with the way they fly around ... so what if we went smaller, and started with an insect, or even spider-like thing.

Hmm, a flying spider that swims? O.o I'm going to have nightmares tonight for sure .. sigh

Praying mantis are pretty agressive, and can fly. Basically they currently - as is - are Land = Air. Moving an insect into water, shouldn't be too tough?

[edit] I was thinking water would be the hard part here, though .. however, I just remembered, there's a diving beetle that seems to handle land/water just fine :) http://en.wikipedia.org/wiki/Great_diving_beetle

They also fly naturally ;) .. so there you go ... got "Diving Beetle" in addition to "Duck" ;) [/edit]

  • $\begingroup$ @DaaaahWhoosh: True, however, just recalled the diving beetle .. added a link and note .. ;) So yeah, quite doable ... $\endgroup$
    – Ditto
    Mar 10, 2015 at 20:08
  • $\begingroup$ That is amazingly unexpected, and quite unsettling D: (yet still a great answer) $\endgroup$ Mar 10, 2015 at 20:10
  • $\begingroup$ Yeah, that's what I thought .. I recalled the diving beetle, did a quick search .. "Holy c**p it flies!??" O.o $\endgroup$
    – Ditto
    Mar 10, 2015 at 20:12

Need it be based on a terrestrial vertebrate? If the creature is essentially hydraulic, it could use the same heavy contractile tissue to divert power to legs, wings or body as required. power transmission and bracing within the wings could be along tendons for lightness. the creature could pounce on land or become airborne from a standing jump from land or water by releasing compressed energy in gas bladders in the legs - along the lines of the compressed-rubber-ball mechanism used by fleas. Hard-tissue trigger-catches could provide the quick release for the leg springs, and similar catches could keep the wing tendons under tension for a gliding take off without the need to power the wings until the creature is aloft. The bladders could be a development of the hydraulic system and might even be liquid filled at other times to act as quasi-muscles at other times. Hydrogen, ammonia and steam are all lifting gasses under terrestrial conditions, and all three could be biologically generated. Unlike hydrogen(?), Ammonia and steam could be quickly reabsorbed, so the bladder could act as a swim-bladder or even aerial balloon if you like. Being hydraulic, the creature could use peristalsis to swim. If it uses external water as the transmission fluid, this system could double as a gill. The bladder mechanism might develop as a lung.

  • $\begingroup$ I really like this answer, it definitely thinks outside the box. Also, welcome to Worldbuilding SE! $\endgroup$ Mar 10, 2015 at 18:40

Something bird-derived seems to be the best bet. You can get birds that are good runners (like ostriches or phorusrhacidae), good swimmers (penguins) and good fliers (birds of prey).


Why not all three? I'd guess the problem would be with buoyancy; flying birds need to be very light in order to be able to fly for significant periods of time. If they get heavy, like chickens do, then they can only manage short-range gliding. Likewise, ostriches have powerful legs that are rather heavy, so there would be some trouble hybridizing a runner with a flier.

You could solve the first problem by giving a flying bird some ballast bladders; simply put, when it wants to dive, it will fill these with water in order to make itself neutrally or negatively buoyant (and maybe also swallow some pebbles or something). Wings can double as fins (as with penguins) and they can keep the feathers from getting wet by insulating them with a layer of oil like ducks do.

Letting it both run and fly will be more difficult; like I said, powerful legs will weight the bird down, and there's not much incentive to run if you can fly, anyways. Some birds that also fly get around by walking (like flamingoes), but those are pretty fragile and probably wouldn't do very well in a fight.


So what could a universal bird look like? I'd imagine something eagle-sized, with notably longer legs, to make it a good runner (so, a predatory flying turkey, basically). It'd have a sharp, raptor beak that would be its primary weapon, and sharp talons which it would use to either grab prey from above or hang onto it while pecking it to death. In water, it would fill its ballast bladders and hunt by snatching fish or other prey with its beak. Its neck would also be longer than an eagle's, somewhere halfway to a heron, since that seems to be advantageous to birds that hund on the ground.

Open Questions

Here's a couple of outstanding issues I wasn't able to figure out:

  • Webbed feet or talons? Webbed feet seem better for locomotion underwater, but might get in the way on the ground and talons are better for grabbing
  • Is this actually feasible with real-world bird muscle and such? Someone would have to run the numbers.
  • Can you actually have wings good both for flying and swimming? It's a headscratcher, but since birds have extremely variable wing geometry, I'm inclined to think it could be arranged.
  • Is it actually advantageous to be able to navigate all three of these environments? Essentially, you're trading specialization and peak characteristics for versatility, which gets tricky if you need to compete with specialists in each environment.
  • $\begingroup$ Great answer; I like the idea of ballast bladders. Also, you made me wonder: what if the bird walked with its wings? That way, it wouldn't need the long, heavy legs. $\endgroup$ Mar 10, 2015 at 14:49
  • 1
    $\begingroup$ @DaaaahWhoosh Well, wings tend to be pretty fragile and break most easily of all the parts of the bird. You can grab an eagle by its talons, shake him vigorously and he will be none the worse for the wear (though it might object with painful - to you - results), but doing the same with wings could fatally injure him. Also, they would need to be well muscled for that, which might make them less suitable for flying. $\endgroup$
    – Mike L.
    Mar 10, 2015 at 14:52
  • $\begingroup$ I really like the point about running when you can fly. I suppose there could be circumstances where it'd be necessary (such as the constant heavy storms of the Dolphin Bat answer) and there could be mechanical advantages (such as the need to suddenly change direction, which is easier on the ground than in the air), but I'd think that in general flying trumps running. $\endgroup$
    – Bobson
    Mar 10, 2015 at 19:39
  • $\begingroup$ @Bobson There are also environments where hunting from above doesn't work very well, such as under a forest canopy. I didn't delve much into that because I focused primarily on the mechanics. $\endgroup$
    – Mike L.
    Mar 10, 2015 at 19:45
  • $\begingroup$ "Above" could simply be a few feet above - it doesn't have to imply far up. Just high enough that you aren't slowed by roots and bushes, and can see past your prey. Although then you can't necessarily go under something to follow it. $\endgroup$
    – Bobson
    Mar 11, 2015 at 4:11

Is it strictly necessary for the creature in question to be able to hunt in all three environments simultaneously? If not, there's a rather simple solution: metamorphosis.

A butterfly navigates air well, but it starts off life as a caterpillar that can't fly at all. A frog begins life as a tadpole that can only live in the water, but eventually morphs into a form that handles both water and land. Based on similar examples in our world, you could construct a creature that goes through different physical forms during different phases of life.

These creatures might start off life as aquatic creatures with the ability to hunt things on or near the water's surface (think of a lungfish that could briefly glide like a flying fish or walk on water like a basilisk lizard). Later in life, they could go through a metamorphosis where their gills disappear and their lungs take over, their leg muscles develop significantly, and their fish-like fins morph into bat-like wings. The result could be something similar to a flying dragon, but with wings that are more developed.

The advantage to this approach is that you avoid some of the problems that others have mentioned regarding triple-threat creatures, such as creatures light enough to fly being too buoyant to hunt well underwater. You also end up with something that's not unbelievably different than existing creatures. Animals that hunt in two of the three media are not uncommon, and the changes during metamorphosis would be less drastic than what we see with some Earth creatures (e.g. butterflies).


The type of creature that flies well is radically different from one that swims well or can burrow into the ground. From an evolutionary standpoint, there is rarely anything to be gained by changing a design of a creature that survives well in one type of environment. In order for a predator to exist that navigates all three media equally well, there would have to be a good reason.

You mentioned the lack of food, however the lack of food means there are few animals in any one environment to sustain a predator. You don't typically see creatures evolve to surpass problems like this because the changes are too radical. It is a bit like asking why gazelles in Africa didn't evolve wheels or wings to escape the cheetahs. Such changes don't happen overnight, and they certainly don't get it right on the first try. Progress in evolution tends to be favorable to conditions that encourage a particular trait. Any mutation in a gazelle that doesn't immediately improve speed is going to get eaten by the cheetah before it has a chance to pass on its genes to its offspring, all the moreso if a gazelle, in the process of evolving "wheels" becomes triple jointed.

Generally creatures that can fly have very few natural predators, since they are the most ellusive of all creatures to catch. Even then, most of these predators are creatures that attack nests, and not while flying because it is very difficult to catch your prey that way. The only way something like this would be possible is if there were predators that easily caught prey in the air. Just like you see flying fish leaping out of the air to temporaneously escape a predator in the water, you might begin to see birds that can dive into the water to escape a flying predator. Once you have creatures that can do this, you might then see an evolution of the predators themselves that could dive with the birds in order to catch them.

However, it wouldn't make sense to have a predator exist without sufficient prey, and this type of prey would only exist with this type of predator (oddly enough, in the food chain, one wouldn't exist without the other). And if this predator does so despite having many food sources, you can see that such a creature couldn't exist.

Evolution encourages traits which cause that creature to perform better without losing any edge, and this type of predator would require too much of a change that it would deteriorate too much its ability to catch prey in other environments to merit the change in the first place.

However, you tend to see many strange creatures in environments where there are many creatures, not few. Perhaps such a predator could exist, but not because there is lack of food but because it itself is prey and must escape predators better specialized in hunting only in the air, or only in water.


What about snakes? They move well on land, can swim, and there are even some that can glide...


  • $\begingroup$ That's gliding, though. Snakes can't fly. Thank God. $\endgroup$
    – KSmarts
    Mar 11, 2015 at 16:47
  • 1
    $\begingroup$ So... dragons maybe? $\endgroup$
    – Dronz
    Mar 12, 2015 at 0:51

I'm going to have to venture a 'no' answer here.

Out of the current species on Earth, a diving fishing bird might best suit your description, but each species tend to specialize...whats advantageous in one environment isn't in another.

And that's the basis of my 'no' answer...a generalized creature that's semi good in every environment will be out competed in all environments by specialized creatures.

Air : Most adaptions to hunt on land and underwater come at the detriment to flight abilities. Legs capable of walking/hunting are nothing but hindrances while flying and this puts them at a large disadvantage when competing with birds of prey that are highly specialized to exist in the air.

Water: Sorta the reverse of above...movement through water is significantly different than movement through the air and trends towards strength over agility. Gills are a distinct advantage here, but kinda useless in the air (in fact, exposed gills/breathing system is a distinct disadvantage for a land based creature that needs to be able to take a hit). A Shark is the ultimate water hunting machine and will out perform / out hunt any creature that is also capable of flying. Seals and whales would (and do) consider almost any flying creature in the water a very easy meal opportunity.

I could do the same for a land based creature as well...powerful jaws and claws are a good method of hunting...neither of which lend itself well to flying. The light bone structure of a creature that can fly would easily make it susceptible to damage from predators (or even prey for that matter). A creature that has gills as well as lungs find themselves with exposed openings in a land fight (gills damage easily)...they might as well be walking around with big targets on them.

Evolution tends to prefer specialization and not generalization...simply because a specialized creature will always out compete a generalized creature in its specialized environment and you are left with a creature that is capable in all environments but unable to compete in any of them...which is a pretty good way of ensuring a species extinction. I'm pretty sure this is why you don't see creatures like this on Earth and find it's highly unlikely that you'll find them in other environments

  • $\begingroup$ Radical seasons maybe? From water frozen in winter to evaporated in summer? Water creatures would have to hibernate or something otherwise. $\endgroup$
    – Brythan
    Mar 10, 2015 at 22:17
  • $\begingroup$ @Brythan - that happens on earth currently...flying creatures migrate seasonally, sea creatures hide under the ice (or don't really notice the season) and land animals either migrate or hibernate. $\endgroup$
    – Twelfth
    Mar 10, 2015 at 22:25
  • $\begingroup$ I'm thinking more in terms of a world-wide season, where there's nowhere to which to migrate. Also more extreme than Earth where it's the oceans freezing or evaporating, not just small pools. $\endgroup$
    – Brythan
    Mar 10, 2015 at 22:38
  • $\begingroup$ Evolution tends to prefer specialization and not generalization, +1. $\endgroup$
    – Mazura
    Mar 11, 2015 at 3:48

A flying penguin?

A swimming dragon?

A winged snake?

A swimming flying squirrel?

A flying humanoid?

A spiked floating hot-air puffer-fish/balloon/tumbleweed?


I'm actually trying to work on a similar concept, apart from two things: the creature is capable of a certain amount of metamorphosis (wings and aquatic adaptations are formed and destroyed as needed, like a tadpole tail) and it does not require nutrition or oxygen from outer sources, meaning it isn't constrained by issues like the amount of energy spent keeping all these parts. However, if we're going for a more traditional predator approach, if suggest either a flying creature like those found in tropical forests, which is also adapted to swimming. Sure, animals like secretary bird and the roadrunner can both run and fly, but their flight isn't as great as an owl's for example. On the other hand, a flying creature that is maneuverable like those found in tropical forests (harpy eagles, as an example) could also fly close to the ground, having the advantage of observing the land from high up, avoiding detection. With land and air mostly covered, there's water. Both flying and swimming are actually very similar activities (transversing a fluid ), with the main difference being the density of the fluid. In this case, a bird or pterosaur which had fin- like tail or other swimming structures, like a water jet, could benefit from their naturally aerodynamic form, needing mostly a way to become heavier, which could be circumvented by having special structures that could hold the liquid they're swimming through or even denser things, such as rocks, being later expelled and making them light again. Hope it helped.


You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .